Known prior art inhalation devices include, for example, those shown in U.S. Pat. Nos. 3,938,516; 3,964,483; 3,973,566; and 4,005,711. In all of these devices a capsule containing a powdered medicament is first opened and then inserted into an opening in the device and held either by friction fit or by the finger pressure of the user. In opening the capsule, however, it is difficult to hold the device in one hand while taking the capsule apart with the other. Usually the user must put the device down and then use both hands to take the capsule apart. Thereafter he must pick up the device and insert the capsule into the appropriate opening. Other devices have been proposed which employ means for opening the capsule after it is inserted into the inhalation device, see for example U.S. Pat. No, 4,014,336. However, with these devices the user sometimes runs the risk of leaving the portion of the capsule that has been removed (generally the top portion of the capsule) within the device thereby possibly adversely affecting the delivery of the powder during inhalation.
With the instant invention, the chance of leaving a portion of the capsule within the device after opening the capsule is eliminated. Further, opening the capsule and inserting the capsule into the device is readily accomplished without havng to put down the device.